The Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) mission of NASA successfully landed on the western Elysium Planitia of Mars on 26 November 2018 (Banerdt et al., 2020), and a few weeks later, deployed the SEIS seismometer for continuous seismic monitoring of Mars (Lognonné et al., 2019). One of InSight's main tasks is to investigate the Martian crust to shed light on the evolution of terrestrial planets (Lognonné et al., 2019;Smrekar et al., 2019) because the crust of Mars has preserved not only the products of early mantle differentiation and magmatism but also information about the sedimentary history and meteorite impacts.To carry out this task, different approaches have been employed. The seismic studies have revealed that the uppermost 100-200 m beneath the landing site are composed of two low-velocity zones (∼0-20 m and ∼30-80 m) and two high-velocity zones (∼20-30 m, and ∼80-200 m) (Carrasco et al., 2022;Hobiger et al., 2021;Kenda et al., 2020). The low-velocity zones are interpreted as brecciated regolith and sediments, while the high-velocity zones represent basaltic layer based on in situ geological investigations (Warner et al., 2022). For structures of the deeper crust, the P-wave receiver functions (RFs) computed from several marsquakes indicate three crus-

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Results of P wave receiver function (RF) analysis (e.g., H‐κ stacking, common conversion point (CCP) stacking, and migration) depend on the velocity models employed. Converted phases of crustal and upper mantle discontinuities are often interfered by multiple reflections from shallower structures, adding further complexity to the interpretation of P wave RF images. In this study, we propose a receiver function velocity analysis technique (RFVAT) that can constrain the velocity structure above discontinuities and remove multiple reflections arising from target discontinuities. By scanning the amplitude spectra of the Ps and PpPs phases, we can obtain precise arrival times of these phases for interfaces above 250 km (errors < 0.13 s) and derive the average velocities and thicknesses of the layers between interfaces in the crust and upper mantle. Synthetic experiments are used to demonstrate that crustal and upper mantle discontinuities can be coherently identified and that multiple reflections can be effectively removed in the CCP stacking images of P wave RFs using the RFVAT even with low signal‐to‐noise ratio data. By applying the proposed RFVAT to real P wave RF data from the northeastern part of the North China Craton, we achieve an improvement in CCP stacking image of lithospheric discontinuities, especially for the lithosphere‐asthenosphere boundary (LAB). Our P wave RF images reveal distinct lateral variations of the LAB depth. The lithospheric thickness extends to ~120 km beneath the central orogenic belt and decreases sharply to ~80 km at the west edge of the eastern block, consistent with previous S wave RF studies.

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The scattering properties of terrestrial planetary bodies can provide valuable insights into their shallow seismic structure, meteoritic impact history, and geological activity. Scattering properties of the shallow crusts of Earth, Mars, and the Moon are investigated by constructing P‐wave receiver functions (PRFs) from teleseismic waveforms with high signal‐to‐noise ratios. The authors’ analysis reveals that strong coda waves lead to significant variations in the PRF waveforms calculated using different time windows, and the stability of the PRF is primarily influenced by the fractional velocity fluctuation. Synthetic PRFs for various scattering media confirm these observations. Comparing the observed and synthetic PRFs, it is found that the fractional velocity fluctuation in the shallow crust is greater than ∼0.2 for the Moon but less than ∼0.2 for Earth and Mars. The authors further discuss possible mechanisms that could have affected the fractional velocity fluctuation and suggest that the distinct fractional velocity fluctuation between the Moon and Earth/Mars is mainly due to differences in the water content of the crustal rocks of the three planetary bodies.